Propelling pencil



`May 19, 1931.

H. FELGER PROPELLING PENG'IL Filed March 14,- 1929' @www Patented May 19, 19.31

.UNITED STATES l HERMANN FELGEB, OF NUREMBERG, GERMIANY PROPELLING PENCIL Application illed March 14, 1929, Serial No. 347,095, and ixi'vGermany March 21, 1928.

rlhis invention relates to a propelling pencil with a lead holder made of four-cornered iiat iron twisted in part to form a screw, the forward feed of which is effected by turning a head which receives the four-cornered part of the piece of at iron so that it cannot turn but can slide therein, the twisted part of the iat iron being guided by a nut iXed in the middle ofthe pencil. The propelling pencil according to the present invention diiers from the known propelling pencils of this kind in this, that the lead holder which is twisted to form a screw is guided in two slot.- ted caps, one of which acts as a nut and is fixed in the middle of the pencil, while the other is fixed in the head piece which is ca- Y pable of' rotating but not of sliding longitudinally. VThis arrangement of the propelling pencil constitutes a considerable improvement and makes it far simpler and cheaper than those of a known kind. The entire mechanism of the propelling pencil consists only of the helically twisted flatV iron strip and two slotted caps, which latter may be made in a very simple manner by pressing or stamping and can be readily inserted in the casing ofthe propelling pencil.

, ln the accompanying drawings a constructiona-l example of the invention is shown,

F ig. l showing the propelling pencil in axial section and Fig. 2 a portion of the twisted` part of the bar with the slotted guide in perspective.

The propelling pencil contains as usual,`

preferably enclosed in a Celluloid or the like envelope l, a casing 2, which tapers at the forward end and is provided at this tapered end 3 with a rifled opening for the lead 4. The lead 4 is carried by a short tube 5 which is fixed to a flat bar 6. The iat bar 6 is twisted over about half its length to form a helix and 'the helical' part 6a extends through a slot corresponding to the cross-sectien of the bar in the end of a cap 'Z which is fixed inside the casing 2. The untwisted rear end of the dat bar 6 slides in a slot, also corresponding to the cross-section of the bar, inthe end of a second cap 8 which is connected to the rear end. of the casing 2, so as not to slide therein, but to be capable of rotating therein, and

extends as to about half its length out of the casing. Over this cap 8 a hollow7 knob 9 is pushed, which is enclosed, similarly to the casing 2,4 with an envelope 10 of Celluloid or the like and the outer wall of which is flush VWith the outer wall of the casing 2.

forward or backward according to the direction of rotation of the knob 9.

The backward motion of the lead 4 is limited by the distance between the rear end of the flat bar 6 and the inner surface of the end wall of the knob 9. rlhe backward motion of the iat bar 6 can only continue until its rear end strikes against this end wall of the knob 9. The distance to which the flat bar 6 and with it the lead 4 can slide with respect to the casing 2 is adjusted when making the propelling pencil, by the distance to which the cap 8 and the knob 9 are pushed one over the other.

rlhroughthe lead carrier being made in the form of a bar with a twisted part and through the employment of a fixed and a rotatable slotted guide for the said bar, the interior` arrangement of the propelling pencil is greatly simplified, cheapened and improved as compared with the known pencils of this kind. lThe twisted part may of course have any pitch, according to the desired rate of forward feed oi the lead. VAll suitable materials may be used as the consti-notional material for the separate parts of the propelling pencil.

What l claim is:

' A. propelling pencil comprising the comn bination with a casing having an opening ier the lead in one end thereof and a lead helder in said casingincluding a flat bartwisted to form ascrew, of guiding means for said lead holder comprisin 'a cap lixed in the middle of the casing an having a slot therein for receiving the twisted portion of `the lead holder so as to act as a nut therefor, a second cap rotatable but not longitudinally displaceable in the casing at the end thereof remote from the end havlng the opening for the lead, 5 said second-mentioned cap having a slot therein for receiving the untwisted portion of the lead holder so as to act as a longitudinal guide for said portion, and a knob on said second-mentioned cap, as and for the purposes set forth.

In testimony whereof I have signed my name to this specification.

HERMANN FELGER. 

